Power switching circuit and system

Abstract

The utility model discloses a power supply switching circuit and system. Relates to the technical field of control, the power supply switching circuit comprises a reference voltage unit, a target processing unit and a target control unit, the reference voltage unit is used for providing reference voltage for the target processing unit; the input end of the target processing unit is connected with the first power supply and the second power supply, the output end of the target processing unit is connected with the input end of the target control unit, and the target processing unit is used for collecting the output voltage of the first power supply and the second power supply and outputting a target signal to the target control unit based on the magnitude relation between the reference voltage and the output voltage; the target control unit determines a target power supply for supplying power to the load based on the target signal, and the target power supply is the first power supply or the second power supply. Through the application, the problem that power supply undervoltage cannot be identified when a relay interlocking mode is adopted to switch the power supply of the power supply line in related technologies is solved; therefore, the problem of unstable power supply to the terminal equipment is solved.

Description

Technical Field

[0001] The present application relates to the field of control technology, and in particular to a power switching circuit and system. Background Art

[0002] Common power distribution fields often require dual power supply of AB phase or BC phase in three-phase electricity to prevent power failure of secondary terminal equipment after a primary line failure. Currently, most applications use simple relay interlocking for switching. This method can achieve voltage switching under normal conditions, but it cannot identify the action behavior after a certain voltage is undervoltage, which may cause the secondary terminal equipment to work in an undervoltage state. In the long run, the backup power supply of the secondary terminal may not be properly charged, resulting in power failure, and then the secondary terminal cannot be opened and closed in an emergency state, eventually causing a power accident.

[0003] Currently, no effective solution has been proposed for the problem that the power supply of the power supply line is switched by means of relay interlocking in the related art, but the problem of power undervoltage cannot be identified, resulting in unstable power supply to the terminal equipment. Utility Model Content

[0004] The main purpose of the present application is to provide a power switching circuit and system to solve the problem that the power supply of the power supply line is switched by relay interlocking in the related art, and the power undervoltage cannot be identified, resulting in unstable power supply to the terminal equipment.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a power switching circuit is provided. The power switching circuit includes: a reference voltage unit, a target processing unit, and a target control unit, wherein the reference voltage unit is used to provide a reference voltage to the target processing unit; the input end of the target processing unit is connected to the first power supply and the second power supply, the output end of the target processing unit is connected to the input end of the target control unit, the target processing unit is used to collect the output voltages of the first power supply and the second power supply, and output a target signal to the target control unit based on the magnitude relationship between the reference voltage and the output voltage; the target control unit determines the target power supply for powering the load based on the target signal, and the target power supply is the first power supply or the second power supply.

[0006] Furthermore, the power switching circuit also includes: a rectifier circuit, wherein an input end of the rectifier circuit is connected to the first power supply and the second power supply, an output end of the rectifier circuit is connected to an input end of the target processing unit, and the rectifier circuit is used to convert the first power supply and the second power supply into a DC power supply.

[0007] Furthermore, the power switching circuit also includes: a voltage conversion unit, wherein the input end of the voltage conversion unit is connected to the output end of the rectifier circuit, and the voltage conversion unit is used to convert the DC voltage output by the rectifier circuit into a target voltage value to power the target processing unit, the reference voltage unit and the DC relay in the target control unit.

[0008] Further, the target processing unit includes: a first processing module, wherein the first processing module is used to collect the output voltage of the first power supply, and output a first target signal to the target control unit based on the magnitude relationship between the reference voltage and the output voltage of the first power supply; a second processing module, wherein the second processing module is used to collect the output voltage of the second power supply, and output a second target signal to the target control unit based on the magnitude relationship between the reference voltage and the output voltage of the second power supply.

[0009] Furthermore, the first processing module includes: a sampling module, wherein the input end of the sampling module is connected to the first power supply, and the output end of the sampling module is connected to a comparator module; and a comparator module, wherein the output end of the comparator module is connected to the input end of the target control unit.

[0010] Further, the target control unit includes: a first DC relay, wherein the input end of the first DC relay is connected to the output end of the first processing module, the output end of the first DC relay is connected to the AC relay, and the first DC relay is turned on or off when receiving the first target signal output by the first processing module; the AC relay, wherein the output end of the AC relay is connected to the load, when the first DC relay is in the on state, the AC relay supplies power to the load through the first power supply, and when the second DC relay is in the on state, the AC relay supplies power to the load through the second power supply; a second DC relay, wherein the input end of the second DC relay is connected to the output end of the second processing module, the output end of the second DC relay is connected to the AC relay, and the second DC relay is turned on or off when receiving the second target signal output by the second processing module.

[0011] Further, the reference voltage unit includes: a voltage regulator, wherein the positive electrode of the voltage regulator is grounded, the negative electrode of the voltage regulator is connected to the input end of the target processing unit, and the reference voltage is output to the target processing unit through the negative electrode of the voltage regulator; a first resistor, wherein the first end of the first resistor is connected to the output end of the voltage conversion unit, the second end of the first resistor is connected to the first end of the second resistor, and the supply voltage output by the voltage conversion unit is received through the first end of the first resistor to enable the reference voltage unit to work; the second resistor, wherein the second end of the second resistor is connected to the reference level of the voltage regulator; and a third resistor, wherein the first end of the third resistor is connected to the second end of the second resistor, and the second end of the third resistor is connected to the positive electrode of the voltage regulator.

[0012] Furthermore, the voltage conversion unit includes: a power driver chip, wherein the input end of the power driver chip is connected to the output end of the rectifier circuit, and the output end of the power driver chip is connected to the input end of the target processing unit, the input end of the reference voltage unit and the input end of the target control unit.

[0013] Further, the sampling module includes: a first diode, wherein the anode of the first diode is connected to the output end of the rectifier circuit, and the cathode of the first diode is connected to the first end of a fourth resistor; the fourth resistor, wherein the second end of the fourth resistor is connected to the first end of the fifth resistor; and a fifth resistor, wherein the second end of the fifth resistor is grounded.

[0014] In order to achieve the above-mentioned purpose, according to another aspect of the present application, a power switching system is provided. The power switching system comprises: a power supply, wherein the power supply comprises a first power supply and a second power supply; and a power switching circuit, wherein the power switching circuit is connected to the power supply, and the power switching circuit is any one of the power switching circuits described above.

[0015] Through the present application, a reference voltage unit, a target processing unit, and a target control unit are adopted, wherein the reference voltage unit is used to provide a reference voltage to the target processing unit; the input end of the target processing unit is connected to the first power supply and the second power supply, the output end of the target processing unit is connected to the input end of the target control unit, the target processing unit is used to collect the output voltages of the first power supply and the second power supply, and based on the magnitude relationship between the reference voltage and the output voltage, output a target signal to the target control unit; the target control unit determines the target power supply for powering the load based on the target signal, the target power supply is the first power supply or the second power supply, which solves the problem in the related art that the power supply of the power supply line is switched by relay interlocking, and the power supply undervoltage cannot be identified, resulting in unstable power supply to the terminal device. In the power switching circuit provided in the present solution, a reference voltage unit, a target processing unit and a target control unit are provided. The input end of the target processing unit is connected to the first power supply and the second power supply, and the output voltage of the first power supply and the second power supply is then collected. The reference voltage unit provides a reference voltage to the target processing unit. The target processing unit outputs a target signal to the target control unit based on the magnitude relationship between the reference voltage and the output voltage. The target control unit determines the target power supply for supplying power to the load based on the target signal. The magnitude relationship between the reference voltage and the output voltage can be used to accurately identify whether the first power supply and the second power supply have an undervoltage problem, thereby achieving the effect of improving the power supply stability to the terminal device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1 is a schematic diagram of a power switching circuit provided according to an embodiment of the present application;

[0018] Figure 2 is a schematic diagram of a reference voltage unit provided according to an embodiment of the present application;

[0019] Figure 3 is a schematic diagram of a voltage conversion unit provided according to an embodiment of the present application;

[0020] Figure 4 is a schematic diagram of a target processing unit provided according to an embodiment of the present application;

[0021] Figure 5 is a schematic diagram of a first processing module provided according to an embodiment of the present application;

[0022] Figure 6 is a schematic diagram of a sampling module provided according to an embodiment of the present application;

[0023] Figure 7 is a schematic diagram of a comparator module provided according to an embodiment of the present application Figure 1 ;

[0024] Figure 8 is a schematic diagram of a comparator module provided according to an embodiment of the present application Figure 2 ;

[0025] Fig. 9 is a schematic diagram of a target control unit provided according to an embodiment of the present application Figure 1 ;

[0026] Fig.10 is a schematic diagram of a power switching system provided according to an embodiment of the present application;

[0027] Among them, 10-reference voltage unit, 20-target processing unit, 30-target control unit, 40-rectifier circuit, 50-voltage conversion unit, 21-first processing module, 22-second processing module, 210-sampling module, 211-comparison module, 301-first DC relay, 302-AC relay, 303-second DC relay, 101-voltage regulator, 102-first resistor, 103-second resistor, 104-third resistor, 501-power driver chip, 2101-first diode, 2102-fourth resistor, 2103-fifth resistor, 60-power supply, 70-power switching circuit. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] The utility model is described below. Figure 1 is a schematic diagram of a power switching circuit provided according to an embodiment of the present application, such as Figure 1 As shown, the power switching circuit includes: a reference voltage unit 10, a target processing unit 20 and a target control unit 30, wherein:

[0032] The reference voltage unit 10 is used to provide a reference voltage to the target processing unit 20; the input end of the target processing unit 20 is connected to the first power supply and the second power supply, and the output end of the target processing unit 20 is connected to the input end of the target control unit 30. The target processing unit 20 is used to collect the output voltages of the first power supply and the second power supply, and based on the relationship between the reference voltage and the output voltage, output a target signal to the target control unit 30; the target control unit 30 determines the target power supply for powering the load based on the target signal, and the target power supply is the first power supply or the second power supply.

[0033] Alternatively, if Figure 1 As shown, the power switching circuit provided by the present application includes a reference voltage unit 10, a target processing unit 20, and a target control unit 30. The output end of the reference voltage unit 10 is connected to the input end of the target processing unit 20, the input end of the target processing unit 20 is connected to the first power supply and the second power supply, the output end of the target processing unit 20 is connected to the input end of the target control unit 30, and the output end of the target control unit 30 is connected to the load.

[0034] The reference voltage unit 10 outputs a reference voltage to the target processing unit 20. The target processing unit 20 samples the output voltages of the first power supply and the second power supply, compares the sampled output voltages with the reference voltage, and outputs a target signal to the target control unit 30 based on the relationship between the reference voltage and the output voltage. The target control unit 30 determines whether the power supply of the load is the first power supply or the second power supply based on the target signal.

[0035] In summary, in the power switching circuit provided by the present scheme, a reference voltage unit, a target processing unit and a target control unit are provided. The input end of the target processing unit is connected to the first power supply and the second power supply, and the output voltage of the first power supply and the second power supply is then collected. The reference voltage unit provides a reference voltage to the target processing unit. The target processing unit outputs a target signal to the target control unit based on the magnitude relationship between the reference voltage and the output voltage. The target control unit determines the target power supply for supplying power to the load based on the target signal. The magnitude relationship between the reference voltage and the output voltage can be used to accurately identify whether the first power supply and the second power supply have an undervoltage problem, thereby achieving the effect of improving the power supply stability to the terminal device.

[0036] Optionally, in the power switching circuit provided in the embodiment of the present application, the power switching circuit also includes: a rectifier circuit 40, wherein the input end of the rectifier circuit 40 is connected to the first power supply and the second power supply, and the output end of the rectifier circuit 40 is connected to the input end of the target processing unit 20, and the rectifier circuit 40 is used to convert the first power supply and the second power supply into a DC power supply.

[0037] In an optional embodiment, the power switching circuit provided in the present application also includes: a rectifier circuit 40, the input end of the rectifier circuit 40 is connected to the first power supply and the second power supply, the output end of the rectifier circuit 40 is connected to the input end of the target processing unit 20, and the rectifier circuit 40 is used to convert the first power supply and the second power supply into a DC power supply.

[0038] It should be noted that the rectifier circuit 40 may be a half-wave rectifier circuit, which converts AC power into DC power, so that the target processing unit 20 can sample and process the output voltages of the first power supply and the second power supply.

[0039] It should be noted that the first power supply and the second power supply mentioned above can be A-phase and C-phase AC power supplies with a phase difference of 120 degrees. The half-wave rectification circuit can ensure that the rectified output is no higher than 310V, thereby protecting the target processing unit 20.

[0040] Optionally, in the power switching circuit provided in the embodiment of the present application, the reference voltage unit 10 includes: a voltage regulator 101, wherein the positive electrode of the voltage regulator 101 is grounded, the negative electrode of the voltage regulator 101 is connected to the input end of the target processing unit 20, and the reference voltage is output to the target processing unit 20 through the negative electrode of the voltage regulator 101; a first resistor 102, wherein the first end of the first resistor 102 is connected to the output end of the voltage conversion unit 50, the second end of the first resistor 102 is connected to the first end of the second resistor 103, and the power supply voltage output by the voltage conversion unit 50 is received through the first end of the first resistor 102 to enable the reference voltage unit 10 to work; a second resistor 103, wherein the second end of the second resistor 103 is connected to the reference level of the voltage regulator 101; and a third resistor 104, wherein the first end of the third resistor 104 is connected to the second end of the second resistor 103, and the second end of the third resistor 104 is connected to the positive electrode of the voltage regulator 101.

[0041] In an optional embodiment, if Figure 2 As shown, the reference voltage unit 10 includes: a voltage regulator 101, a first resistor 102, a second resistor 103 and a third resistor 104. The positive electrode of the voltage regulator 101 is grounded, the negative electrode of the voltage regulator 101 is connected to the input end of the target processing unit 20, the negative electrode of the voltage regulator 101 is the output end of the reference voltage unit 10, and the reference voltage is output to the input end of the target processing unit 20 through the negative electrode of the voltage regulator 101. The first end of the first resistor 102 is connected to the output end of the voltage conversion unit 50, and the first end of the first resistor 102 is the input end of the reference voltage unit 10. The power supply voltage output by the voltage conversion unit 50 is received through the first end of the first resistor 102 to enable the reference voltage unit 10 to work. The second end of the first resistor 102 is connected to the first end of the second resistor 103.

[0042] It should be noted that the voltage conversion unit 50 is used to output a 12V power supply to the reference voltage unit 10 so that the reference voltage unit 10 can work normally. The second end of the second resistor 103 is connected to the reference level of the voltage regulator 101, the first end of the third resistor 104 is connected to the second end of the second resistor 103, and the second end of the third resistor 104 is connected to the positive electrode of the voltage regulator 101.

[0043] like Figure 2 As shown, the reference voltage unit 10 further includes a first capacitor 105 and a sixth resistor 106 , and the first capacitor 105 is in parallel with the voltage regulator 101 . The sixth resistor 106 is connected between the first resistor 102 and the voltage conversion unit 50 .

[0044] It should be noted that the voltage regulator 101 may be a TL431, and the reference voltage output by the reference voltage unit 10 may be adjusted by the first resistor 102, the second resistor 103 and the third resistor 104. In an optional embodiment, the formula Vin*(1+(R 102 +R 103 ) / R 104 ) is calculated to obtain a reference voltage, where Vin is the input voltage of the reference voltage unit 10, for example, 12V. 102 is the first resistor 102, R 103 is the second resistor 103, and R 104 is the third resistor 104 .

[0045] The reference voltage unit 10 can accurately output the reference voltage, and then accurately determine whether the first power supply or the second power supply has an undervoltage problem.

[0046] Optionally, in the power switching circuit provided in the embodiment of the present application, the power switching circuit also includes: a voltage conversion unit 50, wherein the input end of the voltage conversion unit 50 is connected to the output end of the rectifier circuit 40, and the voltage conversion unit 50 is used to convert the DC voltage output by the rectifier circuit 40 into a target voltage value to power the target processing unit 20, the reference voltage unit 10 and the DC relay in the target control unit 30.

[0047] In an optional embodiment, the power switching circuit also includes: a voltage conversion unit 50, the input end of the voltage conversion unit 50 is connected to the output end of the rectifier circuit 40, the output end of the voltage conversion unit 50 is connected to the input end of the target processing unit 20, the input end of the reference voltage unit 10 and the input end of the target control unit 30, and the voltage conversion unit 50 is used to convert the DC voltage output by the rectifier circuit 40 into a target voltage value to power the DC relays in the target processing unit 20, the reference voltage unit 10 and the target control unit 30.

[0048] In an optional embodiment, the power chip in the voltage conversion unit 50 can use the LP2179 non-isolated buck switching power supply constant voltage control driver chip. The chip is suitable for non-isolated Buck with a full range of input voltages of 85VAC to 265VAC. The Buck topology structure can reduce the 310V DC voltage after half-wave rectification and filtering to DC 12V through the internal oscillator of the power chip and MOS tube PWM modulation, providing a low-voltage DC power supply for the subsequent circuit.

[0049] Optionally, in the power switching circuit provided in the embodiment of the present application, the voltage conversion unit 50 includes: a power driver chip 501, wherein the input end of the power driver chip 501 is connected to the output end of the rectifier circuit 40, and the output end of the power driver chip 501 is connected to the input end of the target processing unit 20, the input end of the reference voltage unit 10 and the input end of the target control unit 30.

[0050] In an optional embodiment, the circuit diagram of the voltage conversion unit 50 is as follows: Figure 3 As shown, the voltage conversion unit 50 includes a power driver chip 501, a second capacitor 502, a third capacitor 503, a fourth capacitor 504, a first inductor 505, a second diode 506, a third diode 507, a seventh resistor 508 and a first electrolytic capacitor 509. The input end of the power driver chip 501 is connected to the output end of the rectifier circuit 40, and the output end of the power driver chip 501 is connected to the input end of the target processing unit 20, the input end of the reference voltage unit 10 and the input end of the target control unit 30. Through the above circuit connection relationship, the 310V DC voltage after half-wave rectification and filtering can be converted into DC 12V, providing a stable input voltage for the target processing unit 20, the reference voltage unit 10 and the target control unit 30.

[0051] Optionally, in the power switching circuit provided in the embodiment of the present application, the target processing unit 20 includes: a first processing module 21, wherein the first processing module 21 is used to collect the output voltage of the first power supply, and based on the magnitude relationship between the reference voltage and the output voltage of the first power supply, output a first target signal to the target control unit 30; a second processing module 22, wherein the second processing module 22 is used to collect the output voltage of the second power supply, and based on the magnitude relationship between the reference voltage and the output voltage of the second power supply, output a second target signal to the target control unit 30.

[0052] In an optional embodiment, if Figure 4 As shown, the target processing unit 20 includes a first processing module 21 and a second processing module 22, and the input ends of the first processing module 21 and the second processing module 22 are connected to the output ends of the rectifier circuit 40. For example, the first processing module 21 is connected to the A-phase power supply (for example, the above-mentioned first power supply) output by the rectifier circuit 40, and the first processing module 21 is connected to the C-phase power supply (for example, the above-mentioned second power supply) output by the rectifier circuit 40.

[0053] The first processing module 21 collects the output voltage of the first power supply, and based on the magnitude relationship between the reference voltage and the output voltage of the first power supply, outputs a first target signal to the target control unit 30. The second processing module 22 collects the output voltage of the second power supply, and based on the magnitude relationship between the reference voltage and the output voltage of the second power supply, outputs a second target signal to the target control unit 30.

[0054] In an optional embodiment, after the first processing module 21 collects the output voltage of the first power supply, it compares the reference voltage with the sampled voltage. When the sampled voltage is higher than the reference voltage, the first processing module 21 outputs a high level, otherwise it outputs a low level.

[0055] The first processing module 21 and the second processing module 22 can accurately identify whether the first power supply and the second power supply have an undervoltage problem, thereby achieving the effect of improving the power supply stability of the terminal.

[0056] Optionally, in the power switching circuit provided in the embodiment of the present application, the first processing module 21 includes: a sampling module 210, wherein the input end of the sampling module 210 is connected to the first power supply, and the output end of the sampling module 210 is connected to the comparator module 211; a comparator module 211, wherein the output end of the comparator module 211 is connected to the input end of the target control unit 30.

[0057] In an optional embodiment, if Figure 5 As shown, the first processing module 21 includes a sampling module 210 and a comparator module 211. The input end of the sampling module 210 is connected to the first power supply, that is, connected to the output of the rectifier circuit 40. The output end of the sampling module 210 is connected to the comparator module 211. The output end of the comparator module 211 is connected to the input end of the target control unit 30.

[0058] In an optional embodiment, the sampling module 210 samples the output voltage of the first power supply and inputs the collected voltage value into the comparator module 211. At the same time, the comparator module 211 obtains the reference voltage from the reference voltage unit 10, and then compares the collected voltage value with the reference voltage. When the sampled voltage is higher than the reference voltage, the comparator module 211 outputs a high level to the input end of the target control unit 30, otherwise it outputs a low level to the input end of the target control unit 30.

[0059] The output voltage of the power supply can be accurately sampled by the sampling module 210 , and whether the power supply has an undervoltage problem can be accurately identified by the comparator module 211 .

[0060] It should be noted that the structure of the second processing module 22 is the same as that of the first processing module 21 , which will not be described in detail herein.

[0061] Optionally, in the power switching circuit provided in the embodiment of the present application, the sampling module 210 includes: a first diode 2101, wherein the positive electrode of the first diode 2101 is connected to the output end of the rectifier circuit 40, and the negative electrode of the first diode 2101 is connected to the first end of the fourth resistor 2102; a fourth resistor 2102, wherein the second end of the fourth resistor 2102 is connected to the input end of the comparator module 211; a fifth resistor 2103, wherein the first end of the fifth resistor 2103 is connected to the second end of the fourth resistor 2102, and the second end of the fifth resistor 2103 is grounded.

[0062] In an optional embodiment, if Figure 6 As shown, the sampling module 210 includes a first diode 2101, a fourth resistor 2102, and a fifth resistor 2103. The anode of the first diode 2101 is connected to the output end of the rectifier circuit 40, the cathode of the first diode 2101 is connected to the first end of the fourth resistor 2102, the second end of the fourth resistor 2102 is connected to the input end of the comparator module 211, the first end of the fifth resistor 2103 is connected to the second end of the fourth resistor 2102, and the second end of the fifth resistor 2103 is grounded.

[0063] like Figure 6 As shown, the sampling module 210 also includes a second electrolytic capacitor 2104, an eighth resistor 2105, a ninth resistor 2106 and a filter capacitor 2107, the positive electrode of the second electrolytic capacitor 2104 is connected to the negative electrode of the first diode 2101, the negative electrode node of the second electrolytic capacitor 2104, the eighth resistor 2105 is connected between the fourth resistor 2102 and the input end of the comparator module 211, and the ninth resistor 2106 is connected between the fifth resistor 2103 and the ground.

[0064] It should be noted that the circuit connection relationship between the sampling module in the second processing module 22 and the sampling module 210 is the same, which will not be repeated here.

[0065] In an optional embodiment, the circuit connection relationship of the comparator module 211 is as follows: Figure 7As shown, the comparator module 211 includes: a comparator 2110, a ninth resistor 2111, a tenth resistor 2112, an eleventh resistor 2113, a twelfth resistor 2114 and a fifth capacitor 2115. It should be noted that the comparator 2110 may be a single-channel voltage comparator. A first end of the ninth resistor 2111 is connected to the output end of the sampling module 210, a second end of the ninth resistor 2111 is connected to the third pin of the comparator 2110, a first end of the tenth resistor 2112 is connected to the output end of the reference voltage unit 10, a first end of the eleventh resistor 2113 is connected to the second end of the ninth resistor 2111, a second end of the eleventh resistor 2113 is connected to the first pin of the comparator 2110, a first end of the twelfth resistor 2114 is connected to the input end of the voltage conversion unit 50, a second end of the twelfth resistor 2114 is connected to the first pin of the comparator 2110, and the first pin of the comparator 2110 is also connected to the input end of the target control unit 30, a first end of the fifth capacitor 2115 is connected to the output end of the reference voltage unit 10, and a second end of the fifth capacitor 2115 is grounded.

[0066] In an optional embodiment, the comparator can be a dual voltage comparator LM2903, and the comparison between the sampled voltage of the first power supply and the second power supply and the reference voltage is realized through the two paths of the dual voltage comparator. For example, the circuit connection diagram of the dual voltage comparator LM2903 is as follows: Figure 8 As shown, it includes: a voltage comparator LM2903, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8 and a capacitor C1.

[0067] like Figure 8As shown, the first end of the resistor R1 is connected to the output end of the sampling module 210, the second end of the resistor R1 is connected to the third pin of the voltage comparator LM2903, the first end of the resistor R2 is connected to the output end of the reference voltage unit 10, the second end of the resistor R2 is connected to the second pin of the voltage comparator LM2903, the first end of the resistor R3 is connected to the second end of the resistor R1, the first end of the resistor R3 is connected to the first pin of the voltage comparator LM2903, the first end of the resistor R4 is connected to the output end of the voltage conversion unit 50, the second end of the resistor R4 is connected to the first pin of the voltage comparator LM2903, the first pin of the voltage comparator LM2903, which is also the first output end, is connected to the input end of the first DC relay 301 in the target control unit 30, and the first end of the resistor R5 is connected to the second processing module 22. The output end of the sampling module is connected, the second end of the resistor R5 is connected to the fifth pin of the voltage comparator LM2903, the first end of the resistor R6 is connected to the output end of the reference voltage unit 10, the second end of the resistor R6 is connected to the sixth pin of the voltage comparator LM2903, the first end of the resistor R7 is connected to the second end of the resistor R5, the second end of the resistor R7 is connected to the seventh pin of the voltage comparator LM2903, the seventh pin of the voltage comparator LM2903 is also connected to the input end of the target control unit 30, the first end of the resistor R8 is connected to the output end of the voltage conversion unit 50, the second end of the resistor R8 is connected to the seventh pin of the voltage comparator LM2903, the seventh pin of the voltage comparator LM2903, which is also the second output end, is connected to the input end of the second DC relay 303 in the target control unit 30.

[0068] The voltage comparator LM2903 can accurately determine whether the first power supply and the second power supply have an undervoltage problem, which can effectively prevent the secondary terminal device from operating in an undervoltage state and effectively improve the safety of the secondary terminal.

[0069] Optionally, in the power switching circuit provided in the embodiment of the present application, the target control unit 30 includes: a first DC relay 301, wherein the input end of the first DC relay 301 is connected to the output end of the first processing module 21, the output end of the first DC relay 301 is connected to the AC relay 302, and the first DC relay 301 is turned on or off when receiving the first target signal output by the first processing module 21; an AC relay 302, wherein the output end of the AC relay 302 is connected to the load, when the first DC relay 301 is in the on state, the AC relay 302 supplies power to the load through the first power supply, and when the second DC relay 303 is in the on state, the AC relay 302 supplies power to the load through the second power supply; a second DC relay 303, wherein the input end of the second DC relay 303 is connected to the output end of the second processing module 22, the output end of the second DC relay 303 is connected to the AC relay 302, and the second DC relay 303 is turned on or off when receiving the second target signal output by the second processing module 22.

[0070] In an optional embodiment, the target control unit 30 includes a first DC relay 301, a second DC relay 303, and an AC relay 302. When the first DC relay 301 is in the on state, the first power source supplies power to the load through the AC relay 302, and when the second DC relay 303 is in the on state, the second power source supplies power to the load through the AC relay 302. It should be noted that the AC relay 302 can be a normally closed contact and the first DC relay 301, and a normally open contact is connected to the second DC relay 303, that is, the first power source supplies power to the load as a default state.

[0071] like Fig. 9 The circuit diagram of the target control unit 30 shown in the figure, the target control unit 30 includes a first DC relay 301, a second DC relay 303 and an AC relay 302, and also includes a thirteenth resistor 304, a fourteenth resistor 305, a fifteenth resistor 306, a sixteenth resistor 307, a seventeenth resistor 308, an eighteenth resistor 309, a fourth diode 310, a fifth diode 311, a sixth capacitor 312, a seventh capacitor 313, a first transistor 314 and a second transistor 315.

[0072] like Fig. 9As shown, the first end of the thirteenth resistor 304 is the input end of the first DC relay 301, connected to the output end of the target processing unit 20, that is, connected to the output end of the above-mentioned comparator 2110, the second end of the thirteenth resistor 304 is connected to the first end of the fourteenth resistor 305, the second end of the fourteenth resistor 305 is grounded, the base of the first triode 314 is connected to the second end of the thirteenth resistor 304, the emitter of the first triode 314 is grounded, the collector of the first triode 314 is connected to the second end of the sixth capacitor 312, the first end of the sixth capacitor 312 is connected to the fourth diode The positive electrode of the fourth diode 310 is connected to the output end of the voltage conversion unit 50, the first end of the fifteenth resistor 306 is connected to the collector of the first triode 314, the second end of the fifteenth resistor 306 is connected to the second end of the sixth capacitor 312, the first pin of the first DC relay 301 is connected to the second end of the fifteenth resistor 306, the second pin of the first DC relay 301 is connected to the negative electrode of the fourth diode 310, the fifth pin and the sixth pin of the first DC relay 301 are connected to the first power supply, and the seventh pin ( Fig. 9 The first DC relay 301 L1) is connected to the second pin of the AC relay 302, and the eighth pin ( Fig. 9 ACN) of the first DC relay 301 is connected to the first pin of the AC relay 302.

[0073] The first end of the sixteenth resistor 307 is the input end of the second DC relay 303, connected to the output end of the target processing unit 20, that is, connected to the output end of the comparator 2110. The second end of the sixteenth resistor 307 is connected to the first end of the seventeenth resistor 308, and the second end of the seventeenth resistor 308 is grounded. The base of the second transistor 315 is connected to the second end of the sixteenth resistor 307, and the emitter of the second transistor 315 is grounded. The collector of the second transistor 315 is connected to the second end of the seventh capacitor 313, and the first end of the seventh capacitor 313 is connected to the second transistor 315. 15, the cathode of the second triode 315 is connected to the output end of the voltage conversion unit 50, the first end of the eighteenth resistor 309 is connected to the collector of the second triode 315, the second end of the eighteenth resistor 309 is connected to the second end of the seventh capacitor 313, the first pin of the second DC relay 303 is connected to the second end of the eighteenth resistor 309, the second pin of the second DC relay 303 is connected to the cathode of the second triode 315, the fifth pin and the sixth pin of the second DC relay 303 are connected to the second power supply, and the seventh pin ( Fig. 9 The ACN of the second DC relay 303 in the embodiment is connected to the first pin of the AC relay 302, and the eighth pin ( Figure 7The L2 of the second DC relay 303 in the circuit is connected to the third pin of the AC relay 302. The fourth pin of the AC relay 302 is connected to the eighth pin of the second DC relay 303, the fifth pin and the sixth pin of the AC relay 302 are connected to the seventh pin of the second DC relay 303, and the seventh pin and the eighth pin of the AC relay 302 are connected to the seventh pin of the first DC relay 301, that is, the output of the first DC relay 301 is connected to the coil and the normally open contact of the AC relay 302, and the output of the second DC relay 303 is connected to the normally closed trigger of the AC relay 302, so that the first power supply has power and is powered first, and the first power supply has no power and the second power supply has power and is powered by the second power supply.

[0074] Through the above circuit connection relationship, the output of the first DC relay is connected to the coil and normally open contact of the AC relay; the output of the second DC relay is connected to the normally closed contact of the AC relay, so that when the first power supply is powered, the first power supply is selected to supply power first, when the first power supply is powered off, the second power supply is powered on, and when both the first power supply and the second power supply are powered off, the load is powered off.

[0075] The above-mentioned first DC relay 301 is turned on when the comparator module 211 outputs a high level, thereby realizing power supply to the load through the first power supply. When the comparator module 211 outputs a low level, the first DC relay 301 is in a non-conducting state. At this time, it is necessary to determine whether the second DC relay 303 is in a conducting state. If it is in a conducting state, the load is powered by the second power supply.

[0076] Stable power supply to the load is achieved through the first DC relay and the second DC relay.

[0077] The power switching circuit provided by the embodiment of the present application is through a reference voltage unit, wherein the output end of the reference voltage unit is connected to the input end of the target processing unit, and the reference voltage unit is used to provide a reference voltage to the target processing unit; a target processing unit, wherein the input end of the target processing unit is connected to the first power supply and the second power supply, and the output end of the target processing unit is connected to the input end of the target control unit, and the target processing unit is used to collect the output voltages of the first power supply and the second power supply, and output a target signal to the target control unit based on the magnitude relationship between the reference voltage and the output voltage; a target control unit, wherein the input end of the target control unit is connected to the first power supply and the second power supply, and the output end of the target control unit is connected to the load, and the target control unit determines the target power supply for powering the load based on the target signal, and the target power supply is the first power supply or the second power supply, which solves the problem in the related art that the power supply of the power supply line is switched by relay interlocking, and the power undervoltage of the power supply cannot be identified, resulting in unstable power supply to the terminal device. In the power switching circuit provided in the present solution, a reference voltage unit, a target processing unit and a target control unit are provided. The input end of the target processing unit is connected to the first power supply and the second power supply, and the output voltage of the first power supply and the second power supply is then collected. The reference voltage unit provides a reference voltage to the target processing unit. The target processing unit outputs a target signal to the target control unit based on the magnitude relationship between the reference voltage and the output voltage. The target control unit determines the target power supply for supplying power to the load based on the target signal. The magnitude relationship between the reference voltage and the output voltage can be used to accurately identify whether the first power supply and the second power supply have an undervoltage problem, thereby achieving the effect of improving the power supply stability to the terminal device.

[0078] The embodiment of the present application also provides a power switching system. The power switching system provided by the embodiment of the present application is introduced below.

[0079] Fig.10 is a schematic diagram of a power switching system according to an embodiment of the present application. Fig.10 As shown, the power switching system includes: a power supply 60 and a power switching circuit 70.

[0080] A power supply 60, wherein the power supply 60 includes a first power supply and a second power supply; a power switching circuit 70, wherein the power switching circuit 70 is connected to the power supply 60, and the power switching circuit 70 is any one of the power switching circuits mentioned above.

[0081] Alternatively, if Fig.10 As shown, the power switching system includes a power supply 60 and a power switching circuit 70. The power supply 60 includes a first power supply and a second power supply. The power switching circuit 70 switches the first power supply and the second power supply to achieve stable power supply to the load.

[0082] The power switching system provided by the embodiment of the present application is provided with a power supply, wherein the power supply includes a first power supply and a second power supply; a power switching circuit, wherein the power switching circuit is connected to the power supply, and the power switching circuit is any one of the power switching circuits mentioned above, which solves the problem that the power supply of the power supply line is switched by the relay interlocking method in the related art, and the power supply undervoltage cannot be identified, resulting in unstable power supply to the terminal device. In the power switching circuit provided by the present solution, a reference voltage unit, a target processing unit and a target control unit are provided, the input end of the target processing unit is connected to the first power supply and the second power supply, and then the output voltage of the first power supply and the second power supply is collected, the reference voltage unit provides a reference voltage to the target processing unit, and the target processing unit outputs a target signal to the target control unit based on the magnitude relationship between the reference voltage and the output voltage, and the target control unit determines the target power supply for powering the load based on the target signal, and the magnitude relationship between the reference voltage and the output voltage can accurately identify whether the first power supply and the second power supply have an undervoltage problem, thereby achieving the effect of improving the stability of power supply to the terminal device.

[0083] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A power switching circuit, characterized in that: include: A reference voltage unit (10), a target processing unit (20), and a target control unit (30), wherein: The reference voltage unit (10) is used to provide a reference voltage to the target processing unit (20); The input end of the target processing unit (20) is connected to a first power supply and a second power supply, the output end of the target processing unit (20) is connected to an input end of a target control unit (30), and the target processing unit (20) is used to collect the output voltages of the first power supply and the second power supply, and output a target signal to the target control unit (30) based on the magnitude relationship between the reference voltage and the output voltage; The target control unit (30) determines a target power source for supplying power to a load based on the target signal, wherein the target power source is a first power source or a second power source.

2. The circuit according to claim 1, characterized in that The power switching circuit further includes: A rectifier circuit (40), wherein an input end of the rectifier circuit (40) is connected to the first power supply and the second power supply, an output end of the rectifier circuit (40) is connected to an input end of the target processing unit (20), and the rectifier circuit (40) is used to convert the first power supply and the second power supply into a direct current power supply.

3. The circuit according to claim 2, characterized in that The power switching circuit further includes: A voltage conversion unit (50), wherein an input end of the voltage conversion unit (50) is connected to an output end of the rectifier circuit (40), and the voltage conversion unit (50) is used to convert a DC voltage output by the rectifier circuit (40) into a target voltage value to supply power to the target processing unit (20), the reference voltage unit (10) and a DC relay in the target control unit (30).

4. The circuit according to claim 3, characterized in that The target processing unit (20) comprises: A first processing module (21), wherein the first processing module (21) is used to collect the output voltage of the first power supply, and output a first target signal to the target control unit (30) based on a magnitude relationship between the reference voltage and the output voltage of the first power supply; A second processing module (22), wherein the second processing module (22) is used to collect the output voltage of the second power supply, and output a second target signal to the target control unit (30) based on the magnitude relationship between the reference voltage and the output voltage of the second power supply.

5. The circuit according to claim 4, characterized in that The first processing module (21) comprises: A sampling module (210), wherein an input end of the sampling module (210) is connected to the first power supply, and an output end of the sampling module (210) is connected to a comparator module (211); A comparator module (211), wherein an output end of the comparator module (211) is connected to an input end of the target control unit (30).

6. The circuit according to claim 4, characterized in that The target control unit (30) comprises: a first DC relay (301), wherein an input end of the first DC relay (301) is connected to an output end of the first processing module (21), an output end of the first DC relay (301) is connected to an AC relay (302), and the first DC relay (301) is turned on or off when receiving a first target signal output by the first processing module (21); The AC relay (302), wherein an output end of the AC relay (302) is connected to the load, and when the first DC relay (301) is in an on state, the AC relay (302) supplies power to the load through the first power supply, and when the second DC relay (303) is in an on state, the AC relay (302) supplies power to the load through the second power supply; The second DC relay (303), wherein the input end of the second DC relay (303) is connected to the output end of the second processing module (22), the output end of the second DC relay (303) is connected to the AC relay (302), and the second DC relay (303) is turned on or off when receiving the second target signal output by the second processing module (22).

7. The circuit according to claim 3, characterized in that The reference voltage unit (10) comprises: A voltage stabilizer (101), wherein a positive electrode of the voltage stabilizer (101) is grounded, a negative electrode of the voltage stabilizer (101) is connected to an input terminal of the target processing unit (20), and the reference voltage is output to the target processing unit (20) via the negative electrode of the voltage stabilizer (101); a first resistor (102), wherein a first end of the first resistor (102) is connected to an output end of the voltage conversion unit (50), a second end of the first resistor (102) is connected to a first end of a second resistor (103), and a supply voltage output by the voltage conversion unit (50) is received through the first end of the first resistor (102), so that the reference voltage unit (10) operates; The second resistor (103), wherein a second end of the second resistor (103) is connected to a reference level of the voltage regulator (101); A third resistor (104), wherein a first end of the third resistor (104) is connected to a second end of the second resistor (103), and a second end of the third resistor (104) is connected to a positive electrode of the voltage regulator (101).

8. The circuit according to claim 3, characterized in that The voltage conversion unit (50) comprises: A power driver chip (501), wherein an input end of the power driver chip (501) is connected to an output end of the rectifier circuit (40), and an output end of the power driver chip (501) is connected to an input end of the target processing unit (20), an input end of the reference voltage unit (10), and an input end of the target control unit (30).

9. The circuit according to claim 5, characterized in that The sampling module (210) comprises: a first diode (2101), wherein an anode of the first diode (2101) is connected to an output end of the rectifier circuit (40), and a cathode of the first diode (2101) is connected to a first end of a fourth resistor (2102); The fourth resistor (2102), wherein a second end of the fourth resistor (2102) is connected to a first end of the fifth resistor (2103); A fifth resistor (2103), wherein a second end of the fifth resistor (2103) is grounded.

10. A power switching system, characterized in that: include: A power supply (60), wherein the power supply (60) comprises a first power supply and a second power supply; A power switching circuit (70), wherein the power switching circuit (70) is connected to the power supply (60), and the power switching circuit (70) is the power switching circuit according to any one of claims 1 to 9.

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